Device for humidifying breathing air for artificial respiration

ABSTRACT

A device for humidifying breathing air for artificial respiration of mammals, in particular human beings, includes at least one essentially closed container for receiving water, a first opening for letting in the non-humidified air and a second opening for letting out humidified air, and an inlet for supplying the water to the container. The inlet is located in the upper part of the container, which is adjoined by a tube essentially crossing through the container interior, and on the free end of the tube, a valve is disposed, which limits the level of the water supplied via the tube in such a way that the container bottom in the container interior is essentially covered with water.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for humidifying breathing air forartificial respiration of mammals, in particular of humans, thatincludes at least one essentially closed container for receiving water,a first opening in the container for letting non-humidified air in, asecond opening for letting the humidified air out, and an inlet forsupplying water to the container.

2. Related Art

Devices of this type which in medical terminology are simply called airhumidifiers, and in the English-speaking world “humidifiers”, areemployed both in outpatient care and in the hospital. As the term usedfor the device implies, humidifiers are employed for humidifyingbreathing air in case humans, but also animals, must be artificiallyprovided with air for the most diverse reasons or purposes, or air thatmust be supplied in addition to normal breathing air. It is known thatair for artificial respiration, made available either from air bottleswhich are under pressure, or directly by means of pumping devices, as arule do not have the degree of moisture required for the gentleapplication of artificial respiration to a human or to an animal. Amultitude of devices (humidifiers) of the type mentioned at the outsetare known in the prior art, all of which have the above mentioned basictypical construction to a greater or lesser extent. Since in the priorart the basic construction of these devices, the areas of theirapplication, and the specific applications of humidified breathing airfor humans and for animals are well known, further discussion thereof isnot required.

But to the extent that can be observed, the known devices all have oneand/or the other disadvantage, which will be separately addressed below.It is obvious that in their operation, that is, in the course of theirapplication for the humidifying of breathing air, these devices are notpermitted to exhibit any shortcomings or interferences regarding theirfunctioning. A major problem, which was intended to be overcome in manydifferent constructions, is that in all cases the humidified breathingair leaving the device must not contain water being used in the devicefor humidifying the air, which could get into the lungs of the human oranimal via the breathing air connection between the device and the humanor animal. Without addressing this in greater detail, this could havesevere consequences, even death, for the human or animal to be suppliedwith air.

To prevent this, valve structures of various different types have beenproposed in the humidifier container which are intended to preventwater, which is picked up for humidifying, to escape from the containertogether with the humidified breathing air through the outlet and toreach the human or animal to be supplied with air. The solutionsproposed up to now that are intended to solve or overcome this problemhave the disadvantage, which is unacceptable under any circumstancesbecause of the damage to health connected therewith, that they are allessentially based on the principle that, although a predefined amount ofwater is always being received in the container and replenished (sincethe water in the container is used up by becoming absorbed in the airpassed through the container) nevertheless, in case of malfunction ofthe device that controls the replenishment of the water in thecontainer, the device may fail to prevent water from reaching the humanor animal whose breathing is to be aided via the outlet for thehumidified air, with the disadvantageous results mentioned above, whichare often fatal.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a device of thetype mentioned at the outset, by means of which it is possible by simplemeans and a simple construction to provide the continuously reliablefunctioning of the device, so that the uncontrolled supply of water tothe container is prevented, even in the event of a malfunction, so thatin any case, water cannot reach the outside via the outlet to theexterior for the humidified air, or reach the human or animal to begiven artificial respiration.

This object is attained in accordance with the invention in that thewater inlet is formed in the upper part of the container, to which isconnected a tube, which essentially crosses through the interior of thecontainer, and a valve is arranged on the free end of the tube, whichlimits the level of the water supplied via the tube in such a way thatthe interior container bottom is essentially covered with water.

This extremely advantageous principle permits a construction of thedevice in the interior of the container in such a way that, in case of amalfunction, when water has reached the said predetermined level in theinterior of the container, the water does not have any access to thepart of the container between the inlet for non-humidified air and theoutlet for humidified air. By means of this proposed step the level ofthe water supplied via the tube can be limited in such a way that onlythe container bottom in the interior of the container is covered withwater, or in other words covered up to a few millimeters high inrelation to the container bottom.

The way the invention attains this object has proved to be extremelysafe and also meets the legal requirements and parameters for suchdevices.

In accordance with an advantageous embodiment of the humidifying device,the valve has an essentially cylindrical portion, by means of which itis received in the free end of the tube, and an essentially platelikeportion with which, in a base position, closes off the opening in thefree end of the tube. For supplying water to the container interior, theplatelike portion of the valve is slightly deformed by the flow of waterthrough the tube in the course of the filling process because of thepressure of the water being slightly higher than that prevailing in thecontainer interior, so that as much water can enter as the interiorpressure in the container interior normally permits.

Preferably, the cylindrical portion of the valve has a plurality ofaxially extending grooves, through which the water supplied via the tubecan flow over the platelike portion, as described above, and flow intothe container interior up to the desired height.

Finally, the valve is preferably made of an elastomer material, forexample silicone rubber, which is employed without problems in medicine,and which has the advantage that it can be made highly resilient, sothat the platelike portion in particular can perform its intendedopening and closing functions free of malfunctions over long periods oftime, but still can assure secure seating in the tube by means of itscylindrical portion.

In a further, different advantageous embodiment of the humidifyingdevice, a means is provided which, as a function of the level of thewater in the partial interior space, provides a short circuit, in themanner of a bypass between the inlet for the non-humidified air and theoutlet for the humidified air, that puts the partial interior space outof contact with the water vapor above the surface of the water and, whenthe level drops, again brings the partial interior space intocommunication with the water. The dropped level mentioned in thisconnection need not be absolutely the equal of the level which, inconnection with the attainment in accordance with the invention, limitsthe water in the container interior supplied via the tube. However, in acertain still more different embodiment of the invention, it couldeasily be possible for these two water levels to be of equal height. Inthis advantageous embodiment of the humidifying device, a short circuitis virtually provided in this case between the inlet for the airadmitted into the container and the outlet of the air out of thecontainer, in which case only the remaining moisture in thisshort-circuited area is then used as the humidifying means, while, inaccordance with the invention, escape of water from the device from theoutlet for the humidified air is prevented. In this case, the briefapplication of non-humidified breathing air, or of such air onlycontaining residual moisture, is as a rule harmless, and furthermoretakes place only long enough for the level of the water to fall belowsaid predetermined level, or to be lowered because of outsideinfluences.

In accordance with an advantageous embodiment of the humidifying device,the means includes a float device which floats in the container interioron the water therein and, upon reaching a predetermined level, bumpsagainst a first sealing element connected with the container, andbecause of this interrupts the supply of water to the container. Theadvantage of this embodiment of the means is that no lever elements andhinges are present, which tend to exhibit malfunctions in a wateryenvironment, so that by this step too, as required at the outset,besides the satisfactory and assured functionality, a simple andtherefore also cost-effective embodiment of the humidifying device ispossible, because in many cases it is only required once, and must thenbe disposed of in order to prevent the transfer of germs.

In this connection it is advantageous that the float arrangement of thehumidifying device has a collarlike element, which bumps against thefirst sealing element connected with the container once thepredetermined maximum level of the water in the container has beenreached. Because of this, that is, in the state in which the collarlikeelement has bumped against the first sealing element, the inlet for theair into the container and the outlet for the air from the container areadvantageously essentially enclosed via a remaining partial interiorspace; that is, a bypass, is formed, so to speak, for the air from theinlet for the air into the container and the outlet for the air from thecontainer, so no water can enter into this bypass space, that is, theremaining partial interior space and, as already mentioned generallyabove, although the humidified air to be applied can only stem from theremaining moisture in the partial interior space, no water can enter theoutlet for the air out of the container for supplying air for breathingto a human or an animal. This structure, too, is free of movable partsand can therefore be made available in a functionally safe and alsocost-effective manner.

In accordance with a further, different advantageous embodiment of thehumidifying device, the tube, which is essentially centrally located forthe supply of water to the container, essentially extends into thebottom area of the container, and in this embodiment the float devicepreferably has an essentially central passage, which can be embodied inthe form of a central interior tube, in which the central tube extends.Here, the central tube also has a guide function, so to speak, for thefloat device and a guidance function for the water to be introduced fromthe outside into the container interior, and here, too, there is againthe advantage that no links, hinges or lever elements or the like arepresent for blocking the water, such as those used with devices known inthe prior art. Accordingly, on the one hand a high degree offunctionality is achieved, and on the other a cost-effectiveavailability is assured.

The float device is preferably embodied as an essentially closed,floatable body, which therefore advantageously has no attachment pointsfor being caught in the interior container chamber because of its risingand sinking movements as a function of the force of the water in theinterior container chamber in relation to an essentially horizontalalignment of the container bottom as the plane of reference. Inprinciple, this float body can also be embodied as a hollow element,and, it is also possible to use materials for its construction (seebelow) which have a specific gravity of <1, so that it is lighter thanwater and therefore will float in the water.

The above mentioned collarlike element is advantageously embodied as apart separate from the float device and is fastened on the float device,in which case this embodiment makes possible the construction of thefloat device, on the one hand, and of the collarlike element on theother, from different materials where, for example, the actual floatbody need not have any elastomeric properties, but where the collarlikeelement may need to be made of an elastomer material, since it has asealing function or objective. However, it should be made clear that itis of course possible to form the collarlike element, as well as thefloat device, from the same material, and/or in one piece.

The second sealing element provided in still another advantageousembodiment of the humidifying device, is essentially arranged centrallyin the upper container part, and is essentially formed circular in crosssection and, in addition, advantageously has an essentially encirclingsealing lip. In this case the sealing element is in fact embodied in onepiece with the upper container part and can be formed in the course ofthe forming (molding) process of the upper container part. However, itcan also be produced as a separate part and can be fastened in the uppercontainer part in the course of producing the entire device, for exampleby means of gluing, welding, or by a molding process.

A circumferential sealing lip on the sealing element itself preferablyis embodied in one piece with the sealing element and therefore can alsobe matched in regard to its elasticity to the individual requiredmechanical requirements; that is, the degree of elasticity of thesealing lip can be different from the degree of elasticity of theremainder of the sealing element.

In connection with still another very advantageous embodiment of thehumidifier device in the condition where the supply of water to thecontainer interior is interrupted, the sealing lip rests sealingly onthe float device, in particular free of any additional further sealingmeans. That is, the float device forms one part of the seal by means ofits side facing the sealing lip of the second sealing element, and thesealing lip itself forms the other part of the second seal, so that inthis way the sealing means without further movable parts can be simplyproduced which, avoids malfunction.

In the case where the partial interior space is formed in the manner ofa bypass, the second sealing lip rests sealingly on the float device, inwhich case, as explained above, the float device itself forms therequired sealing counterpart to the sealing lip. That is, the sealinglip and the float device itself constitute the seal, so that it ispossible dispense entirely with other movable or sealing parts ofhumidifying device structures that are prone to malfunction that havebeen used up to now, so that even impacts from the exterior on thehumidifying device largely have no effect, because the float body isembodied in the area of the sealing lip adjoining it in such a way thateven shock effects laterally acting from the outside on the device havepractically no effect, or in other words do not adversely affect thesealing effect.

Advantageously, at least the sealing lip is made of an elastomermaterial, and the collarlike element of the float device also isadvantageously made of an elastomer material. The elasticity of thesealing lip as well as of the collarlike element can be embodied indifferent forms, depending on the construction and use of thehumidifying device, and can be matched to the structural and operationalrequirements of the humidifying device.

As mentioned above, the float device can be made of a metallic or also anon-metallic material however, it is advantageous to make it from aplastic material in order to produce the float device as a uniforminjection-molded element made of a plastic material which, besides thelow weight, the low production costs and the operational dependabilityto be expected, also has the advantage that it is possible to assurefreedom from germs associated with the production process for the floatdevice.

The container housing itself can also preferably be made of a plasticmaterial, preferably from an injection-moldable plastic material, inwhich case preferably the inlet for the supply of water to the containerand the upper container part are made in one piece; that is, thecontainer or the container housing can in fact be produced from plasticin a single work step, in particular an injection-moldable plasticmaterial, because of which it is already possible to assure freedom fromgerms by means of a production process selected in this way, andexpensive procedures for making the humidifying device germ-free can beomitted to a large extent.

Not only can at least the upper container part, and/or at least theinlet for the supply of water, preferably be made of a plastic material,in particular injection-moldable plastic material, but the bottom of thecontainer (which must be combined with the container housing after thehumidifying device has been equipped with the valves and the floatelement before it is closed off in a watertight manner later by a metalcontainer bottom) can advantageously also be made of a plastic material,in particular an injection-moldable plastic material, in order to assurefreedom from germs in the course of producing the container, as can itsindividual parts to also make the humidifying device lighter and able tobe disposed of more easily and therefore more cost-effectively after aone-time use as a rule, since no metallic parts are contained in thehumidifying device in accordance with the invention, making and itpossible to recycle the individual components of the humidifying devicein the simplest way.

The container bottoms known in the prior art used in connection withhumidifying devices are as a rule made of metal, or metal alloys, andthese metallic container bottoms are connected as a rule by means of acomparatively elaborate connection process with the container, or theupper container part, which as a rule is made of a plastic material.

Therefore, in accordance with the invention, the container bottom ispreferably made of a plastic material, which permits a very simpleconnection with the upper container part when the upper container partand the lower container part are made of the same plastic material.

As a rule, the water contained in the upper container part must beheated for the intended formation of steam for achieving the intendedhumidifying of the air; that is, it must be brought up to and maintainedat the temperature which represents a temperature, or a temperaturerange, physiologically suitable for the intended purpose. For thispurpose, the bottom areas of the heating devices are set, or pushed,onto a heating device, which enables a good heat transfer between theheating device and the container bottom.

It has been found that for this purpose a container bottom is bestsuited for rapid heating and the avoidance of heat losses in the courseof the heating process, if it is made of a foil consisting of a plasticmaterial. The plastic material of the container bottom is preferablypolyester, in which the thickness of the container bottom preferablylies in the range between 0.05 to 0.5 mm.

DESCRIPTION OF THE DRAWINGS

The invention will now be described by means of an exemplary embodiment,with reference to the attached schematic drawings, where:

FIG. 1 shows the humidifying device in accordance with the invention ina schematic semi-sectional view, in which the essential elements of thedevice are visible, in a view which is slightly reduced in comparisonwith an actual normal size;

FIGS. 2 to 4 show a view in accordance with FIG. 1, in which therespective interior container chambers are filled with different amountsof water, starting in FIG. 2 with a low water content, then in FIG. 3with an increased water content, and in FIG. 4 with the maximallypossible water content, in which the flow of water into the partialinterior space of the interior container chamber is interrupted;

FIG. 5 shows a perspective view of the humidifying device with aremovable protective ring, by means of which the air inlet and the airoutlet are closed off in the storage state of the humidifying device;and

FIG. 6 shows a perspective view of the valve received in the freeopening of the tube in a greatly enlarged form with the platelikeportion of the valve in a relaxed state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

With reference to FIG. 1, the basic structure of the humidifying device10 will be described.

The humidifying device 10 includes an essentially closed container 13,in which the water, which is used to humidify the breathing air, isreceived. The container 13 has a first opening 15, through which air 16,which is not humidified, is supplied from a separately arranged airsource through a hose or the like. The humidifying device 10, moreover,has a second opening 17, through which air 18, which was humidified inthe interior container chamber 23, is supplied to the human 12 or to ananimal, which is to be supplied with breathing air. Finally, thehumidifying device has an inlet 19 for supplying water 14 to theinterior container chamber 23.

The first opening 15 for the supply of non-humidified air 16, the secondopening 17 for the outlet of the humidified air 18 and the inlet 19 forthe supply of water are arranged in the upper part of the container 13,called the upper container part 231. The inlet and the outlet 16, 18 forthe air are here embodied in the form of connecting elements which,referring to FIG. 1, extend upwardly from the upper container part 231in the form of small tube connectors, so that air hoses can easily beconnected leading to the humidifying device 10 and air hoses leadingaway from the humidifying device 10 to a human 12 or an animal caneasily be connected with the humidifying device 10.

The container 13 also has a container bottom 232, and the uppercontainer part 231 and the container bottom 232 essentially constitutethe container 13. In the embodiments shown in the drawings, thecontainer 13 has only three openings, namely the first opening 15, thesecond opening 17, and an opening constituting the inlet 19 for thesupply of water 14. However, it is also possible, not shown here, toprovide further openings in the upper area of the interior containerchamber 23, from which it is possible, for example, to take watersamples, or to attach or insert temperature sensors for the water 14 andthe humidified air 18. In cross section, the container 13, or the uppercontainer part 231, has the shape of an inverted shallow cup. However,it should be pointed out that the shape of the container 13, or of theupper container part 231 per se, can be embodied as desired as afunction of the intended useful embodiment of the humidifying device 10,for example having a rectangular cross section, or the like.

In the upper container part 231, and annularly enclosing the inlet 19for the water 14, the first opening 15 for the non-humidified air 16,and the second opening for the outlet of the humidified air 18, there isprovided a first sealing element 24, protruding in cross section fromthe upper container part 231 into the interior container chamber 23 andformed in the shape of a ridge, which, as shown in FIG. 4, abuts againsta collarlike element 25, and is arranged at the upper end of the floatdevice 22, as shown. This will be described in more detail furtherbelow.

In connection with the embodiment of the humidifying device shown in thedrawings, the float device 22, which here is essentially embodied so asto be rotationally symmetrical in longitudinal section, is arranged inthe interior chamber 23 of the container, and is intended to be a partof a means 20 which, as a function of the level 21 of the water in theinterior chamber 23 of the container, can be moved back and forthvertically in the direction of the arrow 31. The first sealing element24 also works together with the means 20, or more exactly with the floatdevice 22. The float device 22 is made in such a way that it floats inthe water 14, which water exits via the inlet 19 through a verticallyextending tube 27, which is essentially centrally formed in the uppercontainer part 231, and is located in the interior chamber 23 above thecontainer bottom 232. The tube 27 extends in an essentially centralpassage 29 of the float device 22 and is guided there essentiallycentered by the tube 27. The guidance is such that the frictionalresistance in respect to the tube 27 is very low. Therefore along thetube 27, as a function of the level 21 of the water 14, the float device22 can move in the container interior 23 in the direction of theaforementioned arrow 31, depending on the level of water 14 in thecontainer interior 23. The float device 22 can be made as an essentiallyclosed, floatable body.

The means 20 or float device 22 has an encircling collarlike element 25.It is secured to the float device 22 relative to the upper regions asshown in the drawings, and essentially, with its radially orientedsealing face 250, it protrudes outward, from an imaginary central axisthat passes through the tube 27, in such a way that it is below thefirst sealing element 24.

The means 20 furthermore includes a second sealing element 26 of elasticpolymer material, which is located in the container interior in theupper container part 231, around the inlet 19 for water 14, and which inthis case is essentially a rotationally symmetrical part. The collarlikeelement 25, too, comprises elastic polymer material. The second sealingelement 26 can be made in one piece with the upper container part 231,or it can be made as a separate part and joined, in the course ofassembly of the humidifying device 10, firmly and in sealing fashion tothe upper container part 231. The second sealing element 26 is oppositean upper contact plane 233, in depicted in the drawings, which is radialrelative to the tube 27 and protrudes away from it; this contact planecooperates with an encircling sealing lip 30 of the second sealingelement 26 and interrupts the supply of water 20 to the partial interiorspace 230 of the container 13 indirectly, when the first sealing element24 rests on the radial sealing face 250 and the second sealing element26 likewise rests on the radial sealing face 250.

The reference numerals used in the drawings apply equally to FIGS. 2, 3,4, 5 and 6, although some of the reference numerals have been left outfor the sake of clarity, especially in FIGS. 2, 3 and 4.

FIGS. 2-4 will now be described, which show a basic or open mode forwater 14, a medium water filling mode in FIG. 3, and a filled level forwater in FIG. 4, in which the partial interior space 230 is closed offfrom the remainder of the container interior 23. FIG. 4 shows what isvirtually a safety state of the device 10 for a human being or ananimal, as will be discussed in detail hereinafter. The first opening 15for letting in air and the second opening 17 for letting out thehumidified air 19 each communicate with an air source 11, not shown, orwith the human being 12 to be respirated, and the inlet 19 communicateswith a source of water 14 for humidifying the air 11, 16, 18 in thecontainer interior 230.

When the device 10 is started up, first water 14 is supplied, so that acertain level 21 of the water 14 is established in the containerinterior 23.

From a water source, not shown here, water 14 is fed into the inlet 19of the device 10. The water source is at a pressure that is slightlyhigher than the pressure in the container interior 23. The water 14strikes a valve 35 disposed on the free end 270 of the tube 27. Thevalve 35 is shown in FIG. 5 in terms of its basic construction. Thevalve 35 has an essentially cylindrical portion 350 and an essentiallyplatelike portion 351. With its cylindrical portion 350, the valve 35 isseated in the free end 270 of the tube. With the platelike portion 351,the opening 271 of the free end 270 of the tube 27 is closed. At leastthe platelike portion 351 of the valve 35 comprises a highly elasticelastomer material, such as silicone rubber.

The cylindrical portion 350 of the valve 35 has a plurality of axiallyextending grooves 352, through which water can flow in the direction ofthe opening 271 of the free end 270 of the tube 27.

Since the pressure in the container interior 24, that is, in aninitially water-free state, is initially set such that the externalpressure, with which the water, by way of the valve 35 and with theattendant slight pivoting of the platelike portion downward, in terms ofFIG. 5, flows in the direction of the arrow 353, is greater, water 14 isguided via the valve 35 into the container interior 23 until such timeas the level 21 of the water supplied via the tube 27 at which thecontainer bottom 232 in the container interior 23 is essentially coveredwith water is reached. The level 21 is determined by the mechanicalconstruction of the device 10 and by the prevailing or desired pressureconditions of not only the water 14 supplied but also of the breathingair 11 supplied, or of the humidified air 18 that is carried away.

If the container bottom 232 is covered with water 14, once a certainlevel 21 is reached, the pressure in the container interior 23 will haveincreased as a consequence, so that the platelike portion 351 movesupward, in terms of FIG. 5, in the direction of the arrow 353, so thatthe platelike portion 351 closes the opening 271 of the free end 270 ofthe tube 27, and no further water can enter the container interior 23.This is the normal operating state of the device 10, as shown in FIG. 2.For the process of humidifying the breathing air 11 as it passes throughthe device 10, it suffices if only the container bottom 323 be coveredwith water 14, to at most a few millimeters deep. This also limits theenergy required for heating the water 14, to generate the water vapor140 in the container interior.

If water is improperly supplied to the device 10, for instance due tothe device 10 being operated incorrectly or because the valve 35 (thatis an important function element of the device) 10 is defective, thesituation can arise in which water 14 undesirably enters the containerinterior 23 by the way described above.

With water 14 flowing in, the level 21 of the water 14 in the containerinterior 23 will rise, so that the float device 22, as part of the means20, moves upward in the direction of the arrow 31 in FIG. 3. If water 14continues to be supplied, the level 21 of the water 14 in the containerinterior 23 rises, and the float device 22, with its collarlike element25 or in other words the sealing face 250 of the collarlike element 25,bumps against the first sealing element 24. Even if water continues tobe supplied, the float device 22 cannot rise farther upward in thedirection of the arrow 31, because the motion is limited in the verticaldirection, in terms of the drawings, by the contact of the first sealingelement 24 with the collarlike element 25 of the float device 22. Whenthe collarlike element 25 has bumped against the first sealing element24, the inlet of the air 16 into the container 13 and the outlet of theair 18 from the container 13 are short-circuited, essentially in themanner of a bypass, via a remaining partial interior space 230, so thatthe air 18 necessary for the artificial respiration can be carried fromthe second opening 17 and supplied to the person 12 or animal. In thiscase, the breathing air 11 is not humidified, since the course via thebypass does not permit any contact with the water vapor 140 in thecontainer interior 23. Because of the essentially simultaneous contactof the second sealing element with the collarlike element 25, no water14 can get into this remaining partial interior space 230, since thesecond sealing element 26 also enters into sealing engagement with acorrespondingly embodied surface—see above—of the float device 22 andthus preventing the water 14 from entering the partial interior space,as shown in FIG. 4, via the passage 29 between the tube 27 and the floatdevice 22.

Thus in accordance with the invention, during continuous operation, anddepending on the level 21 of the water 14 in the container 13, the flowof water 14 into the container 13 is interrupted on reaching apredetermined level 21, and the flow of water 14 into the container 13is permitted if the level 21 is not reached. If problems arise in thecourse of operation of the device 10, in which water 14 is introducedinto the container interior 23 beyond the desired level 21, the accessof the water 14 to the partial interior space 230 is prevented so thatthe breathing air 11 for a person 12 of an animal does not contain water14. Thus according to the invention, no complicated valve parts, whichare vulnerable to malfunction, are needed in order to ensure that waternever reaches the vicinity of the outlet for the humidified air 18, andthus one can speak of a quasi-self-regulating system.

In the embodiment of FIG. 5, the humidifying device 10 of the inventionis provided with a removable shipping securing means or shipping cap 32,which during storage and shipment, and also when the device happens notto be in use, covers the vicinity of the tube neck of the first opening15 or air inlet, the vicinity of the second opening 17 or air outlet,and the vicinity of the inlet 19 for the water 14, this last not beingdirectly visible in FIG. 5. Together with the shipping cap 32, rodlikeprojections that protrude through the first opening 15 and the secondopening 17 can be provided, which in this state, as a virtual shippingholder 33, 34, keep the float device 22 pressed against the containerbottom 232. If the shipping cap 32 is pulled off upward, by a slightpull in the direction of the arrow 31, the first opening 15 and thesecond opening 17 as well as the air inlet 19 for water 14 areuncovered, and simultaneously, the two rodlike shipping holders 33, 34joined to the shipping cap 32 are removed, and the humidifying device 10is then available for its intended use.

The invention claimed is:
 1. A device for humidifying breathing air forartificial respiration of mammals, comprising: at least one essentiallyclosed container for receiving water, the container having an interior,a first opening for letting non-humidified air into the interior, asecond opening for letting out humidified air from the interior, and awater inlet for supplying the water to the container, wherein the waterinlet is provided in an upper part of the container, which is adjoinedby a tube essentially crossing through the container interior, and avalve is disposed on a free end of the tube that limits the level of thewater supplied via the tube in such a way that a container bottom in thecontainer interior is maintained essentially covered with water, whereinthe container bottom is made of plastic material, and the device forhumidifying breathing air further including means which, as a functionof the level of the water in the container interior, short-circuits thewater vapor out of contact with air to be humidified above the surfaceof the water in the manner of a bypass between the inlet ofnon-humidified air and the outlet of the humidified air, andreestablishes contact when the level of water drops in a partialinterior space of the container.
 2. The humidifying device according toclaim 1, wherein the valve has an essentially cylindrical portion thatis received in the free end of the tube, and an essentially platelikeportion which closes the opening of the free end of the tube.
 3. Thehumidifying device according to claim 2, wherein the cylindrical portionhas a plurality of axially extending grooves.
 4. The humidifying deviceaccording to claim 1, wherein the valve comprises elastomer material. 5.The humidifying device according to claim 4, wherein the elastomermaterial comprises silicone rubber.
 6. The humidifying device accordingto claim 1, wherein the means includes a float device, which floats inthe water in the container interior and when the predetermined level ofwater is reached, bumps against a first sealing element connected to thecontainer, and thereby interrupts the supply of water into thecontainer.
 7. The humidifying device according to claim 6, wherein thefloat device has a collarlike element, which bumps against the firstsealing element connected to the container.
 8. The humidifying deviceaccording to claim 7, wherein, when the collarlike element bumps againstthe first sealing element, the inlet of the air into the container andthe outlet of the air out of the container is essentiallyshort-circuited via the remaining partial interior space.
 9. Thehumidifying device according to claim 6, wherein the tube extendsessentially into the bottom region of the container.
 10. The humidifyingdevice according to claim 9, wherein the tube is a central tube in thecontainer, and wherein the float device has an essentially centralpassage into which the central tube extends.
 11. The humidifying deviceaccording to claim 6, wherein the float device comprises an essentiallyclosed, floatable body.
 12. The humidifying device according to claim 7,wherein the collarlike element comprises a part that is separate fromthe float element and is secured to the float element.
 13. Thehumidifying device according to claim 6, further comprising a secondsealing element disposed essentially centrally to the upper part of thecontainer and essentially circular in cross section.
 14. The humidifyingdevice according to claim 13, wherein the second sealing elementincludes an essentially encompassing sealing lip.
 15. The humidifyingdevice according to claim 14, wherein the sealing lip, when the partialinterior space functions in the manner of the bypass, rests sealingly onthe float device.
 16. The humidifying device according to claim 14,wherein at least the sealing lip comprises an elastomer material. 17.The humidifying device according to claim 7, wherein the collarlikeelement of the float device comprises an elastomer material.
 18. Thehumidifying device according to claim 6, wherein the float deviceessentially comprises plastic material.
 19. The humidifying deviceaccording to claim 1, wherein the inlet for the supply of the water intothe container and the upper part of the container are formed in onepiece.
 20. The humidifying device according to claim 19, wherein atleast the upper part of the container and/or at least the inlet for thesupply of the water is made of plastic material.
 21. The humidifyingdevice according to claim 1, wherein the plastic material comprises afilm.
 22. The humidifying device according to claim 1, wherein theplastic material is polyester.
 23. The humidifying device according toclaim 1, wherein the thickness of the container bottom is in the rangefrom 0.05 to 0.5 mm.
 24. The humidifying device according to claim 1,wherein the container bottom is configured so that the device forhumidifying breathing air is configured to be placed on a heatingdevice.
 25. The humidifying device according to claim 1, wherein theupper part of the container is made of the same plastic material as thecontainer bottom.